Boron Carbon Nitride Semiconductor Modified with CeO2 for Photocatalytic Reduction of CO2 with H2O: Comparative Study

Abstract Boron carbon nitride (BCN) is an emerging metal-free catalyst for CO2 photocatalytic reduction. However, the fast electron-hole recombination as well as the weak absorption for ultraviolet-visible (UV-vis) light are still challenging for the activity upgrading of BCN. In this paper, a BCN/CeO2 heterostructure via N-O-Ce bonding was fabricated by a urea-assistant heat-precipitation technique and confirmed by XRD, FT-IR, SEM, TEM and XPS characterizations. For CO2 photoreduction with H2O as reducing agent, the BCN/CeO2 heterostructure delivered an obviously enhanced catalytic performance with CO yield of ca. 6-fold that of BCN. UV-vis diffuse reflectance spectrophotometer (DRS), electrochemical impedance spectroscopy (EIS) and transient photocurrent response measurements revealed that the electron-hole separation efficiency and charge transfer are efficiently promoted on CeO2/BCN heterostructure, along with the boosted light harvesting in visible and ultraviolet light range. Furthermore, based on the photo(electro)chemical and photocatalytic results, a possible CO2 photocatalytic reduction mechanism was proposed.